Lubricant return means for sewing machines



LUBRICANT RETURN MEANS FOR SEWING MACHINES Filed Feb. 15, 1957 Oct. 20, 1959 H. HACKLANDER IN VEN TOR. Hans Hack/under ZITTORNEY 2 Sheets-Sheet 1 Oct. 20, 1959 H. HACKLANDER 2,909,242

LUBRICANT RETURN MEANS FOR SEWING MACHINES Filed Feb. 15, 1957 2 Sheets-Sheet 2 v 6 9 4 90 u j:

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1 i a a 63 E so INVENTOR. Hans Hack/under A TORNEY United States Patent Ofiice 2,909,242 -Patented Oct. 20, 1959 2,909,242 LUBRICANT RETURN MEANS FOR SEWING MACHINES Hans Hacklander, Warren Township, N.J., assign'or to The Singer Manufacturing Company, Elizabeth, N.J., a corporation of New Jersey Application February 15, 1957, Serial No. 640,530 9 Claims. (Cl. 184-6) The present invention relates to sewing machines and particularly to a'means for returning to the lubricant reservoir of a sewing machine the excess lubricant delivered to the operating mechanism of the machine.

The primary object of this invention is to provide a lubricant return means for a sewing machine for returning lubricant to a main reservoir, which means is simple, economical to. produce, easy to operate, eflicient, dependable and durable.

Having in mind the above and other objects that will be evident from an understanding of this disclosure, the invention comprises the devices, combinations and arrangementsof parts as illustrated in the presently preferred embodiment of the invention which is hereinafter set forth in such detail as to enable those skilled in the art readily to understand the function, operation, construction and advantages of it when read in conjunction with the accompanying drawings in which:

Fig. 1 is a horizontal sectional view through the bed of a sewing machine having applied thereto a lubricant return means constructed in accordance with the present invention;

Fig. 2 is a top plan View perse of the pump shown on the machine in Fig. 1. V Fig. 3,is a fragmentary sectional view takenv substantially on the line 33 of Fig. 1. V

i Fig. 4 is a fragmentary sectional View taken substantially on the line 44 of Fig. 3.

The present invention, for purposes of illustration, is

herein disclosed as appliedto the sewing machine forming the subject matter of my copending application Serial No. 609,836, filed September 14, 1956 ,to which refer ence may be had for a more complete understanding of the machine. The machine is herein disclosed only insofar as is believed to be necessary to obtain an understanding of the present invention.

With reference-to the drawings, there'is illustrated a bedfll' that forms a part. of thefraine of a sewing machine. .;The bed 1 includes a bottom plate 2 and walls upstanding from the bottom plate 2 including a front Wall 3, a rear wall 4, and end walls 5 and 6. The plate 2 .and walls 3, 4, Sand 6 define a portion of a closed lubrication compartment 7 that 'is divided by an apertured transverse bearingwall 8 into a bed section 9 and a standard sectionltl which are in 'open communication with each other. The end wall 6 is spaced from the end of the bottom plate 2 to provide a space 11in the bed bed section 9 of the closed compartment 7 and-has mounted thereon a spur gear 15 that meshes witha similar gear 16 on a feed actuating shaft 17. The feed actuating shaft extends through the bed section 9 and is journaled in the walls 6 and 8, the outboard end portion of said shaft projecting through the wall 6 andinto the space 11 outside the closed compartment 7 with the outboard end of the shaft 17 journaled in a bearing lug 18. Mounted upon the feed actuating shaft 17 is an adjustable eccentric 19 connected by a link 20 to a crank 21 on the end of a feed advance shaft 22 journaled in the wall 6 and in a lug '23. Mounted on the feed advance shaft 22 is a rocker 24 to the upper end of which 7 is mounted one end of a feed bar 25.

Also mounted upon the free end of the main shaft 12 in the .bed section 9 of the closed compartment 7 is a bevel gear 26 that meshes with a similar gear 27 on a looper drive shaft 28 journaled transversely-of the bed in the rear wall 4 and in a lug-29.: Mounted upon the free end of the shaft28 is a crank plate 30 having a skewed crank pin 31 which, through a universal. connection including a link 32, imparts both oscillation and re ciprocation to a looper bar 33 journaled in the wall 6 and extending through the space 11 with the free end thereof journaled in the lug 18. Within the space 11, a looper carrier 34 is mounted on the looper bar'33. The above looper mechanism is described and claimed in my copending application Serial No. 609,836.

To provide for automatic lubrication of the sewing machine, the closed compartment 7 constitutes a reservoir and is filled with lubricant to a predetermined level that is high enough so that the oil sling 14 and other parts of the operating mechanism such as the gears 15 4 conduct the lubricant deposited in the cavity 36, by the 1 that is'outside the closed compartment 7 for accommo dating certain portions of the operating mechanisms in the bed; such as the looper and feed mechanisms.

The operating mechanism in the bed 1 includes a driven main shaftlZ extending through the standard section 10 of the closed compartment 7 and journaled in the walls i .5 and 8, Withinrthe section,10, there is mounted on the shaft 12 a crank 13 for operating the needlemechanism (notfshown) and an oil sling 14, such as disclosed and claimed in my copendin g application SerialNo. 553,-

806. The shaft 12 extends through the wall 8into the splash-lubrication of the mechanism in the closed compartment 7, to various bearing surfaces of the mechanism in the space 11. At the same time, other bearing surfaces of the mechanism in the space 11 are separately lubricated such as by the feed advance shaft 22 which extends through the wall 6 into the closed compartment 7 and is provided with an oil collecting cavity 39.

To insure adequate lubrication of the mechanism in the space 11, lubricant is provided in excess, and the excess drops off onto'the underlying portion of the bottom plate 2. In accordance with the present invention, this excess lubricant is returned to the main lubricant reservoir which is in the closed compartment 7 by a pump means comprisinga pump 40 secured to the underside of the bottom plate 2 by three pairs of screws 41, 42 and 43. Each of the pairs of screws 41, 42 and 43 is arranged with one of the screws thereof on each side of the pump 40, and each of the screws projects through an car 44 r (Fig. 4) extending laterally'therefrom and is threaded walls 50 and 51, the free edges or top of which terminate in a plane and are seated against a machinedsurface on the bottom plate 2 of the bed 1 directly beneath the space 11. The screws 42 and 43 are arranged ateach of the corners of the well 47 and a gasket 52 is disposed between the'top of the walls 48, 49, 50 and 51 and the bottom plate 2 to provide an oil-tight seal between the well 47 and the bottom plate 2. At the opposite end of the pump 40 there is formed a boss 53 the top or free edge of which terminates in the plane defined by the top of the walls of the well 47. The boss 53 is disposed directly beneath the closed compartment 7 against a machined surface on the bottom plate 2. The screws 41 are arranged at each side of the boss 53 and a gasket 54 is disposed between the top of the boss 53 and the bottom plate 2 to provide an oil-tight seal.

The body portion .of the pump 40 is provided with a cylindrical bore 55 that constitutes a piston chamber, the end of the bore 55 beneath the space 11 being closed by a cap 56 secured in place by screws 57, a gasket 58 being interposed between the cap'56 and the end of the body portion of the pump 40. At the opposite end, the bore 55 is closed by a cap 59 secured in place by the screws 60 and having a gasket 61between the cap 60 and the end of the body portion of the pump 40. Extending through a bore centrally of the cap 59 is a piston rod 62, a sealing ring 63 being provided to prevent the lubricant from escaping along the rod. Outwardly of the cap 59, the rod '62' is bent at a right angle to provide a handle 64. Within the'bore or chamber 55 is a piston 65 secured on the end of the rod 62 by a nut 66 threaded onto the reduced threaded end 67 of the rod. A sealing ring 68 is disposed between the piston 65 and the wall of the chamber 55. The piston 65 is provided with a plurality of through bores 69 that are closed by a valve plate 70 held against the side of the piston 65 by a spring 71 which is backed by a collar 72 secured on the rod 67 by a set screw 73. The valve plate 70 is arranged on that side of the piston 65 which is toward the cap 59 or in other words, on the side that is towardthe end of the chamber 55 underlying the closed compartment 7. Thus, the valve 70 will be closed as the piston 65 is moved from the left to the right as seen in Fig. 3 and will be effective to force lubricant toward the end of the chamber 55 underlying the closed compartment 7, and the valve 70 will tend to open against the action of the spring 71 when the piston 65 is moved from the right to the left as seen in Fig. 3.

The inlet for the chamber 55 comprises an aperture 74 provided in the bottom plate 2 of the bed 1 within the space 11 directly above the well 47 and adjacent to the end wall of the well 49 which is the wall that is close to .the transverse center of the chamber 55. A sleeve or tube 75 is press fitted into the aperture 74, the tube being covered by a screen or filter 76 held in place by a retaining ring 77 secured by screws 78 threaded into the bottom plate 2. A cover plate 79 is disposed above'the filter 76 to prevent lint and other material from falling directly onto the filter 76, the plate being secured by the screws 78 andspaced above the upper surface of the bottom plate 2 by spacers 80 to provide a shallow opening between the cover plate 79 and the bottom plate 2 for the lubricant that drops onto the bottom plate 2 to flow through the filter 76 and into the well 47.

The well 47 is provided with a transverse wall 81 (Fig. 3) extending between the side walls 50 and 51, which wall 81 is lower in height than the walls 50 and 51 so that there will be an opening between the top of the wall 81 and the bottom plate 2. Thus, there is formed a sump 82 defined by the side walls 50 and 51 and end wall 49 of the well and the transverse wall 81 and the tube 75 extends below the level of wall 81 and thus below the level of the lubricant in the sump so that there is obtained a vapor seal between the well 47 and the space 11. At the same time, the sump 82 constitutes a sediment trap for any lint or other material coming through ,the filter 76. Asecond sediment trap is provided by a wall-83 spaced from the wall 81 and arranged transversely of the well 47 between'the sidewalls 50 and 51. 'The wall. 83, together'with thewall 81 and the side walls 58 and 51 of thewell 47, form a sump 84 into which the lubricant flowing over the top of the wall 81 enters. Beyond the wall 83, there is provided an aperture 85 in the bottom of the well 47 which aperture opens into the piston chamber 55 and through which aperture the lubricant flowing over the top of the wall 83 enters the chamber 55. The aperture 85 opens into the chamber 55 at a point spaced from the end defined by the cap 56 by an amount adequate to accommodate the piston 65 so that when the piston 65 is in the extreme left position as seen in Fig. 2, the lubricant draining into the chamber 55 will enter to the right of the piston, or in other words, on that side of the piston toward the discharge end of the chamber 55.

At the opposite end of the chamber 55 there is an outlet or discharge means comprising a well 86 in the top of the boss 53 that is connected to the chamber 55 by a bore 87. To provide clearance for the feed shaft 17 the well 86 (Fig. 4) is elongated laterally of.the boss 53, the end of the well 86 communicating with an internally threaded aperture 88 into which is threaded a tube 89 that rises vertically in the closed compartment 7 to a point that is above the normal level of the lubricant in the bottom thereof. To prevent the lubricant being splashed about in the closed compartment 7 from entering the tube 89 the top thereof is closed by a cap 90 (Fig. 3) which is secured to the tube 89, as by brazing. The cap 90 has a counterbored lower end 91 that has an internal diameter greater than the outer diameter of the tube 89, thus providing a shield 92 on the bottom of the cap, which shield is spaced from and overhangs the top of the tube 89. The tube 89 has a plurality of-outlet apertures 93 in the area covered by the shield 92.

During operation of the machine, the excess lubricant delivered to the operating mechanism in the space 11 drops onto the underlying portion of the bottom plate 2 of the bed 1, and drains through the filter 76 into the well 47 and through the aperture 85 into the pump-piston chamber 55 in which it accumulates. Periodically at relatively infrequent intervals, since the amount of the excess lubricant is small and the capacity of the chamber 55 is quite large, the operator pulls the handle 64 of the piston rod 62. As the handle moves to the right in Fig. 3, it first closes the inlet aperture 85 and the accumulated lubricant in the chamber'55 is forced toward and out the discharge opening 87, up the tube 89 and out the openings 93 back into the closed compartment 7. The piston 65 is then manually returned to the left end of the chamber 55 beyond the outlet aperture 85 as seen '65 are forced out through the inlet apertures 85 and 74,

with the plate 79 serving .to prevent this return discharge of the piston 65 from spurting out of the aperture 74 in the bottom plate 2. The valve plate 70 provides for relief of the air and lubricant that is trapped behind the piston 65 after it passes the inletaperture 85, and at the same time, Will open in the manner of a relief valve at any time during the return stroke when there is more than a predetermined pressure on the piston, which condition would be apt to occur when there is a large accumulation of lubricant behind the piston since the lubricant would offer considerable resistance to a pressure forcing it back through the inlet passageway for the chamber 55.

Having thus set forth thenature of this invention, what I claim herein is:

1. In a sewing machine having a frame, operating mechanism carried by said frame, a lubricant reservoir on said'frame, means for delivering lubricant from said reservoir to said operating mechanism, and means for returning excess lubricant from said operating mechanism to said reservoir comprising a pump chamber, discharge means forconducting lubricant from said chamber'to said reservoir, means including a normally open -1inlet' for'draiiiing thesexcess Iubrican't into said chamber,

and means for closing said inlet and for. forcing the lubricant'collected in said chamber out said discharge means to said reservoir. t

2. In a sewing machine having a frame, operating mechanism carried by said frame, a lubricant reservoir on said frame, means for delivering lubricant from said reservoir to said operating mechanism, and means for returning excess lubricant from said operating mechanism to said reservoir comprising a pump having a piston chamber, a piston disposed in saidchamber for sliding movement longitudinally of said chamber, discharge means for conducting lubricant from said chamberto said reservoir, means including a normally openinlet for draining the excess lubricant. into said chamber at a point between comprising a pump having a piston chamber, a piston disposed in said chamber for sliding movement longitudinally of said chamber, discharge means for conducting lubricant from said chamber into said closed compartment, means including a normally open inlet for draining the excess lubricant into said chamber at a point between said discharge means and said piston, and 'means for moving said piston longitudinally of said chamber to close said inlet and to force the lubricant collected in said chamber out said discharge means into said closed compartment.

4. In a sewing machine having a frame including a closed splash-lubricated compartment and operating mechanism disposed partly in said compartment and partly outside said compartment, means for delivering lubricant from said compartment to the operating mechanism disposed outside said compartment, and means for returning to said compartment the excess lubricant delivered to said operating mechanism outside said compartment comprising a chamber, discharge means for conducting lubricant from said chamber into said compartment comprising a tube extending into said compartment and communicating with said chamber, a cap on said tube for closing the end of said tube having a shield disposed in spaced relation about the closed end thereof, said tube having an opening therethrough in the area surrounded by said shield, means for draining the excess lubricant into said chamber, and means for forcing the lubricant collected in said chamber out said discharge means into said compartment.

5. In a sewing machine having a frame including a closed splash-lubricated compartment and operating mechanism disposed partly in said compartment and partly outside said compartment, means for delivering'lubricant from said compartment to the-operating mechanism disposed outside said compartment, and means for returning to said compartment the excess lubricant delivered to the operating mechanism outside said compartment comprising a pump having a piston chamber, a piston disposed in said chamber for sliding movement longitudinally of said chamber, discharge means for conducting lubricant from said chamber into said closed compartment comprising a tube extending into said compartment and communicating with said chamber adjacent to the one end thereof, a cap on said tube for closing the end of said tube and having a shield disposed in spaced relation about the closed end thereof, said tube having an opening therethrough in the area surroundcxi by said shield, means for draining the excess lubricant into said' chamber at a point between said discharge means and said piston, and means for moving said piston longitudinally of said chamber to force the excess lubricant collected in said chamber out said discharge means into said closedcompartment.

6. In a swing machine having a frame including a closed splash-lubricated compartment 'and operating mechanism disposed partly in said compartment and partly outside said compartment, means for delivering lubricant from said compartment to the operating mechanism disposed outside said compartment, and means for returning to said compartment the excess lubricant delivered to the operating mechanism outside said compartment comprising a pump having a piston chamber and a well connected with said chamber by a bore having an opening into said chamber spaced from one end of said chamber, a piston disposed in .said chamber for slidingmovement longitudinally of said chamber, discharge means for conducting lubricant from said chamber into said closed compartment, means for draining the excess lubricant into said well and having an outlet into said well that is spaced from the bore, a wall extending across said well between the outlet and the bore and having a height that is less than the depth of the well to form a sediment trap from which the lubricant -fiows over the top of the wall and through the bore into said chamber, and means for moving said piston longitudinally of said chamber to force the lubricant collected in said chamber out said discharge means into said closed compartment.

7. In a sewing machine having a frame including a closed splash-lubricated compartment and operating mechanism disposed partly in said compartment and partly outside said compartment, means for delivering lubricant from said compartment to the operating mechanism disposed outside said compartment, and means for returning to said compartment the excess lubricant delivered to the operating mechanism outside said compartment comprising a pump having a piston chamber and a well connected with said chamber by a bore having an opening into said chamber spaced from one end of said chamber, a wall extending across said well and of a height that is less than the depth of the well to define a sediment trap, means having an outlet below the level of the lubricant in said sediment trap for draining the excess lubricant into said sediment trap from which lubricant flows over the top of said wall and through said bore into said chamber, discharge means for conducting lubricant from said chamber into said closed compartment, a piston disposed in said chamber for sliding movement longitudinally of said chamber, and means for moving said piston longitudinally of said chamber to force the lubricant collected in said chamber out said discharge means into said compartment.

8. ,In a sewing machine having a frame including a bottom plate and a closed splash lubricated compartment, operating mechanism disposed partly in said compartment and partly outside said compartment above said bottom plate, means for delivering lubricant from said compartment to the operating mechanism disposed outside said compartment with the excess of the delivered lubricant deposited on said bottom plate, a pump having a piston chamber, discharge means for conducting lubricant from said chamber into said closed compartment, means for draining the excess lubricant deposited on said bottom plate into said chamber including an aperture in said bottom plate, a cover plate over the aperture in spaced parallel relation to said bottom plate, a piston disposed in said chamber for sliding movement longitudinally of said chamber, and means for moving said piston to force the lubricant collected in said chamber out said discharge meansinto said closed compartment.

9. In a sewing machine having a frame including a bottom plate and a closed splash-lubricated compartment, operating mechanism partly in said compartment and partly outside said compartment above said bottom plate,

' 7 means for delivering lubricant from said compartment to .the operating mechanism disposed outside said .compartment with the excess of the delivered lubricant deposited on said bottom plate, and means for returning to ,said compartment the excess lubricant delivered to the operating mechanism outside said compartment comprising a pump secured to the underside of said bottom plate and having a piston chamber, Walls extending upwardlytfrom said pump at one end of said chamber and defining a well connected with said chamber by a bore, the free edges of said walls terminating in a plane and seated against the underside of said bottom plate beneath the operating mechanism outside said compartment, said pump having an opening from said well to said chamber, a boss extending upwardly from said pump at the other end of said chamber and seated against the underside of said bottom plate beneath said compartment, said boss having a bore extending into said chamber, said bottom plate having an opening into said compartment communicating with said bore and providing for the return of lubricant from said'ch'amberinto said compart- References Cited in-the file of this 'patent UNITED STATES PATENTS 649,027 Woodard May 8, 1890 1,934,877 Otis Nov. 14, 1933 1,969,927 Hacklander Aug. 14, 1934 2,202,817 Sardu June 4, 1940 2,237,273 Hacklander Apr. 1, 1941 2,502,346 Sauer Mar. '28, 1950 

